Having trouble switching amp channels on Mesa 2-channel Mini Rectifier 25

[John H]

I recently purchased a Mesa Mini Rectifier 25 amp. It's a 2 channel amp. Came with a 1 button footswitch and a standard TS cable to connect the footswitch to the amp. I have a PBC/6x controller. I tried every combination I can think of in the global setting for the function switch and still no luck. Am I missing something? Thank you